Magnetization evolution in connected pore systems. III. Fluid flow

The time evolution of the magnetization in a fluid-filled porous medium is studied for the case in which the pore fluid carries a steady current. Both the mean lifetime and the spectrum of relaxation rates are calculated with effective-medium theory. The structure of the spectrum of relaxation rates is found to be very sensitive to the fluid flow. Thus the spectrum of relaxation rates is a valuable detector of fluid flow or of features of the pore-space geometry when the flow is known